This invention relates to tablet preparations.
In addition to the active ingredient(s), a tablet basically contains: (1) diluent, (2) binder, (3) disintegrator, and (4) lubricant.
Diluent is a substance or a mixture of substances added to a tablet to increase the bulk in order to make the tablet a practical size for compression.
Binder is a substance or a mixture of substances added to a tablet to impart a cohesiveness to the tablet formulation which insures the tablet remaining intact after compression.
Disintegrator is a substance or a mixture of substances added to a tablet to facilitate its breakup or disintegration after administration.
Lubricant is a substance or a mixture of substances added to a tablet to improve the flowability and to prevent adhesion of the tablet material to the surface of the dies and punches, reduce interparticle friction, and facilitate the ejection of the tablets from the die cavity.
There are currently three general methods of tablet preparation: (1) wet-granulation method, (2) dry-granulation method, and (3) direct compression. All three methods have disadvantages.
Wet-granulation method is the most widely used method. Its popularity is due to the greater probability that the granulation will meet all the physical requirements for the compression of good tablets. Its chief disadvantages are the number of separate steps involved and the time and labor necessary to carry out the procedure. The steps involved in the wet-granulation method are: (1) weighing, (2) mixing, (3) granulation, (4) screening the damp mass after granulation, (5) drying (6) dry screening (7) lubrication, and (8) compression.
Dry-granulation method is generally used when tablet ingredients are sensitive to moisture or are unable to withstand elevated temperatures during drying. This method eliminates a number of steps but still includes (1) weighing, (2) mixing, (3) dry granulation, (4) dry screening, (5) lubrication, and (6) compression. However, this method requires that the tablet ingredients must have sufficient inherent binding or cohesive properties for dry granulation.
Direct compression consists of compressing tablets directly from ingredients without wet or dry granulation. This method comprises only three steps: (1) weighing, (2) mixing, and (3) compression. However, it has two major disadvantages: (1) the active ingredients must possess inherent binding and cohesive properties, and/or (2) the diluents and/or binders must be capable of imparting the compressible characteristics. To acquire these properties, the ingredients must be subjected to preprocessing step such as wet granulation, dry granulation, or other granulation processes such as spheronization, spray drying, and crystallization.
The present invention discloses a new method of tablet preparation which is very simple and cost effective.
The method of the present invention consists of compressing tablets directly from powdered materials without modifying the physical nature of the materials using gelatin. All ingredients used in this method do not have to undergo preprocessing step such as wet granulation, dry granulation, or other granulation processes such as spheronization, spray drying, and crystallization.
An aqueous solution of gelatin has often been used in wet granulation. However, its dry form, powder or granules, has never been directly used in tablet compression.
It is an object of this invention to provide a simple method of preparing tablets in which gelatin, in its dry form, with its strong binding, cohesive, and hydrophillic properties, can be utilized as tablet diluent, and/or binder, and/or disintegrator.
The method of tablet preparation in this invention comprises only three simple steps: (1) weighing, (2) mixing, and (3) compression.
The following discussion details procedure of the tablet preparation using gelatin.
Gelatin used in this invention can be powder or granules and in concentrations from 0.1% to 99.9% of the tablet weight.
STEP 1xe2x80x94WEIGHING: Active ingredient(s), gelatin, and other ingredient(s) are accurately weighed.
STEP 2xe2x80x94MIXING: Active ingredient(s), gelatin, and other ingredient(s) are added, one item at a time, into a suitable blender and mix for an appropriate length of time.
STEP 3xe2x80x94COMPRESSION: The mixture from STEP 2 is compressed into tablets.